Methods and apparatus for low heat spray drying

ABSTRACT

Methods and apparatus provide for spray drying a liquid product into a dried powder without applying heat, including: forming a slurry including a liquid solvent, a carrier, and an active ingredient; applying an electrostatic charge to the slurry; atomizing the charged slurry to produce a plurality of electrostatically charged, wet particles; suspending the electrostatically charged, wet particles for a sufficient time to permit repulsive forces induced by the electrostatic charge on at least some wet particles to cause at least some of such particles to divide into wet sub-particles; and continuing the suspending step, without the presence of any heated drying fluids, for a sufficient time to drive off a sufficient amount of the liquid solvent within most of the wet particles to leave a plurality of dried particles (the powder), each dried particle containing the active ingredient encapsulated within the carrier.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation under 35 USC 120 of U.S. patent application Ser.No. 14/606,771 filed Jan. 27, 2015 in the names of Charles P. Beetz,Robert Corbett, and David Salem for “METHODS AND APPRATUS FOR LOW HEATSPRAY DRYING,” which in turn is a continuation-in-part under 35 USC 120of U.S. patent application Ser. No. 13/245,369 filed Sep. 26, 2011 inthe names of Charles P. Beetz, Robert Corbett, and David Salem for“METHODS AND APPRATUS FOR LOW HEAT SPRAY DRYING,” and issued Jan. 27,2015 as U.S. Pat. No. 8,939,388, which in turn claims the benefit under35 USC 119 of U.S. Provisional Patent Application No. 61/386,762, filedSep. 27, 2010 in the names of Charles P. Beetz, Robert Corbett, andDavid Salem for “METHODS AND APPRATUS FOR LOW HEAT SPRAY DRYING.” Thedisclosures of U.S. patent application Ser. Nos. 14/606,771 and13/245,369 and U.S. Provisional Patent Application No. 61/386,762 arehereby incorporated herein by reference in their respective entireties,for all purposes.

FIELD

The present disclosure relates to methods and apparatus for spray dryinga liquid product into a dried powder without applying heat, or applyingsubstantially low amounts of heat.

DESCRIPTION OF THE RELATED ART

Spray drying is a method of producing a dry powder from a liquid orslurry by rapidly drying with a hot gas (usually air). Spray dryingtechnology has existed since the late 1800's and has continually evolvedover the past century.

The spray drying process begins with a liquid solvent, commonly water,containing dissolved or suspended components such as an emulsion. Thesuspension includes a substance to be encapsulated (the load) and anamphipathic carrier (usually some sort of modified starch), which arehomogenized as a suspension in the liquid solvent. The load is typicallysome constituent component(s) of a food, fragrance, medicament, etc.,and the homogenized suspension is often referred to as a slurry.

Spray dryers use some type of atomizer, such as a spray nozzle, todisperse the slurry into a controlled spray having some relativelycontrolled droplet size. Depending on the process requirements, dropletsizes may range from about 10 to 500 microns in diameter. The mostcommon applications require droplet sizes in the 50 to 200 micron range.

In conjunction with atomization, the slurry is fed into a dryingchamber, usually a tower into which heated air is also introduced. Thetemperature of the air as it enters the drying chamber is well over theboiling point of water, usually in the range of 180-200° C. The heatedair supplies energy for evaporation of volatile components of the liquid(the water) from the droplets. As the water evaporates, the carrierforms a hardened shell around the load, producing a dried powder.

Reference is made to FIG. 1, which illustrates a conventional spraydrying system 50 and associated process. The process begins with makinga slurry of ingredients. The ingredients include a liquid solvent, suchas water 1, a carrier 2, and active ingredient(s) 3. In the typicalprocess, the water 1 and carrier 2 are added into the solution tank 4while stirring. The active ingredient 3 is then added to the tank 4 andstirred into the slurry. The active ingredient is either emulsified inthe carrier fluid system or dissolved into it. In order for conventionalspray drying processes to be commercially viable, typical slurryviscosities must be in the range of about 10-300 mPa-s.

The slurry formed in the solution tank 4 is delivered to an atomizer 6using a feed pump 5 or other means of conveyance. The slurry enters theatomizer 6 and leaves the atomizer as a spray of liquid droplets 8, andthe droplets 8 are introduced into a drying chamber 7. Concurrently, afeed of air is heated by a process heater 11 and supplied into thedrying chamber 7 by a blower 10. The water evaporated from the droplets8 enters the heated air as the atomized liquid droplets 8 dry to formsolid particles after exposure to the incoming heated air.

The dried powder leaves the dryer chamber 7 along with the water vaporladen air, and is carried to a cyclone separator 12, which removes thedried particles from the circulating air stream and deposits theparticles into a collection container 13. The water vapor laden airexits the collection container 13 and enters a baghouse 14, where veryfine particles are removed before the water vapor laden air is sent intoa condenser 9, via blower 15. The condenser 9 removes the water vaporfrom the process air, and the collected water may be re-used ordiscarded.

One of the prominent attributes of the traditional spray drying processis the high temperature of the inlet gas (typically on the order of 200°C.) leaving the heater 11 and entering the drying chamber 7, as well asthe temperature of the outlet gas exiting the drying chamber 7, which isusually in excess of 100° C. Although the liquid droplets 8 are injectedinto the high temperature environment within the chamber 7, the droplets8 do not actually reach the inlet gas temperature. The droplets 8,however, do become heated to a point at which considerable portions ofdesired constituents of the droplets (i.e., portions of the load) areundesirably modified, such as evaporated and/or oxidized. Theundesirable modification to the load (load loss) leads to a reduction inflavor (in the case of food loads), a reduction in aroma (in the case offragrances), etc. Essentially, evaporation and heat degradation of theload lowers the performance characteristics of the final powder product,and therefore results in a significant degradation of performance incommercial use and a significant loss of revenue.

The above disadvantageous characteristics of the conventional spray dryprocess have resulted in many process modifications and emulsionformulations to compensate for heat induced alterations in the load.This is especially true in the pharmaceutical industry, where excessiveheating during spray drying leads to degradation of the activeingredient in a powdered medicament. This also presents a challenge toflavorists in the powdered flavor industry to design flavor formulationsthat can survive the drying process and deliver acceptable (althoughsignificantly flawed) flavor characteristics.

In view of the above, there are needs in the art for new methods andapparatus for carrying out the spray drying process, which reduce oreliminate the disadvantageous characteristics of the conventional spraydry process.

SUMMARY

Methods and apparatus for spray drying a liquid product into a driedpowder without applying heat provide for: forming a slurry including aliquid solvent, a carrier, and an active ingredient; applying anelectrostatic charge to the slurry; atomizing the charged slurry toproduce a plurality of electrostatically charged, wet particles;suspending the electrostatically charged, wet particles for a sufficienttime to permit repulsive forces induced by the electrostatic charge onat least some wet particles to cause at least some of such particles todivide into wet sub-particles; and continuing the suspending step,without the presence of any heated drying fluids, for a sufficient timeto drive off a sufficient amount of the liquid solvent within most ofthe wet particles to leave a plurality of dried particles (the powder),each dried particle containing the active ingredient encapsulated withinthe carrier.

Preferably, a temperature of the non-heated drying fluid is less thanabout 100° C. at introduction into the drying chamber, such as at leastone of: less than about 75° C. at introduction into the drying chamber;less than about 45° C. at introduction into the drying chamber; lessthan about 35° C. at introduction into the drying chamber; less thanabout 30° C. at introduction into the drying chamber; and at about anambient temperature of a room within which the drying chamber islocated.

The methods and apparatus may further provide for subjecting theelectrostatically charged, wet particles to a non-heated drying fluidwithin a drying chamber to drive off the liquid solvent. Alternativelyor additionally, the methods and apparatus may further provide fordehumidifying the non-heated drying fluid prior to introduction into thedrying chamber. Alternatively or additionally, the methods and apparatusmay further provide for applying one or more electric fields within thedrying chamber to urge at least one of the wet particles and the dryparticles to travel in a direction defined from an inlet end of thedrying chamber to an outlet end of the drying chamber.

The methods and apparatus may further provide for controlling one ormore of a viscosity of the slurry during formation a ratio of waterwithin the slurry during formation, such that one or more of: (i) theviscosity of the slurry at the atomization step is at least one of:greater than about 300 mPa-s; greater than about 350 mPa-s; greater thanabout 400 mPa-s; greater than about 500 mPa-s; greater than about 600mPa-s; greater than about 700 mPa-s; between about 500-16,000 mPa-s; andbetween about 1000-4000 mPa-s; and (ii) the ratio of water within theslurry at the atomization step is at least one of: between about 20-50weight percentage; between about 20-45 weight percentage; between about20-45 weight percentage; between about 20-40 weight percentage; about 30weight percentage.

The apparatus may include a drying chamber, including an inlet end, anoutlet end, and an internal volume within which the liquid product isdried, where the drying chamber is formed from a non-electricallyconductive material.

Additionally or alternatively, a first electrode may be located at ornear the inlet end of the drying chamber; and a second electrode may belocated at or near the outlet end of the drying chamber, whereapplication of a source of voltage potential between the first andsecond electrodes induces an electric field within the drying chambersufficient to urge particles of the liquid product, produced by way ofatomization, from the inlet end toward the outlet end of the dryingchamber. Preferably, the first and second electrodes are disposedexternal to the drying chamber, yet induce an electric field within theinternal volume of the drying chamber by virtue of the formation of thedrying chamber from the non-electrically conductive material.

The apparatus may additionally or alternatively include a nozzleoperating to atomize a slurry to produce a plurality of wet particles,where the slurry includes a liquid solvent, a carrier, and an activeingredient. The apparatus may further include at least one electrodeoperating to contact the slurry and apply an electrostatic chargethereto, such that the nozzle operates to produce a plurality ofelectrostatically charged wet particles. The at least one electrode maybe disposed within the nozzle such that the slurry contacts theelectrode and becomes electrostatically charged while flowing from aninlet end to an outlet end of the nozzle.

A dried powder produced using one or more aspects of the invention mayinclude: a plurality of dried particles, which individually contain anamount of final active ingredient encapsulated within a carrierresulting from drying a slurry containing an initial active ingredient,a liquid solvent and the carrier, wherein: the initial active ingredientincludes one or more constituent components, at least one of which isamong one or more principle molecular types from which at least one of adesirable food, flavor, fragrance, medicament, and pigment is obtained;the final active ingredient includes one or more of the constituentcomponents corresponding with those of the initial active ingredient asmodified by the drying of the slurry; and wherein a weight percentage ofat least one of the one or more principle molecular types in the finalactive ingredient is within about 5% of a weight percentage of thecorresponding principle molecular types in the initial activeingredient.

Alternatively or additionally, the weight percentage of at least one ofthe one or more principle molecular types in the final active ingredientmay be within about 3%, 2% or 1% of a weight percentage of thecorresponding principle molecular types in the initial activeingredient.

Additionally or alternatively, a dried powder produced using one or moreaspects of the invention may include: a plurality of dried particles,which individually contain an amount of active ingredient encapsulatedwithin a carrier, wherein: the active ingredient includes one or moreconstituent components, at least one of which is among one or moreprinciple molecular types from which at least one of a desirable food,flavor, fragrance, medicament, and pigment is obtained; and wherein aweight percentage of at least one of the one or more principle moleculartypes in the active ingredient does not vary by more than about 5%during aging of the dried powder during any period of elevatedtemperature of about 95° F. up to about 1000 hours.

Additionally or alternatively, the weight percentage of at least one ofthe one or more principle molecular types in the active ingredient doesnot vary by more than about 3%, 2% or 1% during aging of the driedduring any period of elevated temperature of about 95° F. up to about1000 hours.

Other aspects, features, and advantages of the present invention will beapparent to one skilled in the art from the description herein taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purposes of illustration, there are forms shown in the drawingsthat are presently preferred, it being understood, however, that theinvention is not limited to the precise arrangements andinstrumentalities shown.

FIG. 1 is a system for spray drying a liquid product into a dried powderthrough the convention application of heated air in accordance with theprior art;

FIG. 2 is a system for spray drying a liquid product into a dried powderwithout employing heated air in accordance with one or more aspects ofthe present invention;

FIG. 3 is a cross-sectional view of an atomizer that may be employed inthe system of FIG. 2 in order to produce a plurality of droplets from aslurry in accordance with one or more aspects of the present invention;

FIG. 4 is a cross-sectional view of a distal end of an atomizer that maybe employed in the atomizer of FIG. 3 in accordance with one or moreaspects of the present invention;

FIG. 5 is a perspective, exploded view of certain components of thedistal end of the atomizer of FIG. 4 in accordance with one or moreaspects of the present invention;

FIG. 6 is a schematic, side view of a drying chamber that may beemployed in the system of FIG. 2 in accordance with one or more aspectsof the present invention;

FIG. 7 is an image of dried powder non-fibrous particles produced usingthe system of FIG. 2;

FIG. 8 is an image of a cross-section through one of the dried powderparticles of FIG. 7 showing the encapsulation of the load within thecarrier;

FIG. 9 is an image of dried powder fibers produced using the system ofFIG. 2;

FIG. 10 is an image of a cross-section through one of the dried powderfibers of FIG. 9 showing the encapsulation of the load within thecarrier; and

FIG. 11 is a graph illustrating certain properties of dried powderparticles produced using the system of FIG. 2 as compared with theconventional spray drying process.

FIGS. 12-19 are graphs illustrating retention of properties by spraydried powders of the present disclosure.

DETAILED DESCRIPTION

With reference to the drawings, wherein like numerals indicate likeelements, there is shown in FIG. 2 a system 100 for spray drying aliquid product into a dried powder without employing heated air inaccordance with one or more aspects of the present invention. The system100 includes some of the same or similar elements as in the system 50 ofFIG. 1, which elements have the same reference designators.

By way of a high level description, the system 100 includes a dryingchamber 107 into which a slurry is fed by way of a feed pump 5 (orequivalent conveying mechanism). The slurry enters an atomizer 106 andleaves the atomizer as a spray of liquid droplets 108, which areintroduced into the drying chamber 7. Concurrently, a feed of non-heatedfluid (such as air or another suitable gas) is supplied into the dryingchamber 107 by a blower 10. The supplied air may be subjected todehumidification (via dehumidifier 110) prior to introduction into thedrying chamber 107. The atomized liquid droplets 108 dry to form solidparticles after exposure to the incoming air. Water evaporates from thedroplets 108 and enters the air within the drying chamber 107. Driedpowder leaves the drying chamber 107 along with the water vapor ladenair, and is carried to a cyclone separator 12, which removes the driedparticles from the circulating air stream and deposits the particlesinto a collection container 13. The water vapor laden air exits thecollection container 13 and enters a baghouse 14, where very fineparticles are removed before the water vapor laden air is sent into acondenser 9, via blower 15. The condenser 9 removes the water vapor fromthe process air, and the collected water may be re-used or discarded.

There are a number of very significant differences between the systemsof FIGS. 1 and 2. Among these differences is the fact that the system100 and related spray drying process does not use a heated fluid (e.g.,air) to dry the atomized droplets within the drying chamber. The use ofnon-heated air is directly counter to the conventional and acceptedwisdom in the spray drying art. Indeed, there is no known prior artspray drying process or system that does not use significantly heatedair (on the order of 200° C.) in the drying process, despite the factthat the load loss associated with the heating process is wellunderstood by skilled artisans. The reason that conventional spraydrying processes call for heated air, however, is that artisans havefailed to develop an alternative to using heated air that results insuitable (albeit degraded) dried powder product.

Among the reasons that non-heated air may be used in the spray dryingsystem 100 and process is that the slurry is not conventional. Ingeneral, the slurry includes a liquid solvent, a carrier, and an activeingredient. The liquid solvent is usually water, however, other suitablesolvents may be employed if needed or desired. The carrier is usually amodified starch. The active ingredient may be any desirable singleconstituent component or a combination of constituent components, atleast one of which is among one or more principle molecular types fromwhich at least one of a desirable food, flavor, fragrance, medicament,pigment, probiotic, bacteria, etc. is obtained.

Formation of the slurry is controlled such that regulation of at leastone of the viscosity, the amount of liquid solvent (e.g., water), orother suitable metric relating to the water content of the slurry, isobtained. For example, the formation of the slurry may includecontrolling a viscosity of the slurry such that the viscosity at theatomization step is at least one of: greater than about 300 mPa-s;greater than about 350 mPa-s; greater than about 400 mPa-s; greater thanabout 500 mPa-s; greater than about 600 mPa-s; greater than about 700mPa-s; between about 500-16,000 mPa-s; and between about 1000-4000mPa-s. Additionally or alternatively, the formation of the slurry mayinclude controlling a ratio of water within the slurry such that theratio of water within the slurry at the atomization step is at least oneof: between about 20-50 weight percentage; between about 20-45 weightpercentage; between about 20-45 weight percentage; between about 20-40weight percentage; and about 30 weight percentage. In order to providesome information as to the significant differences between a slurryaccording to one or more embodiments of the invention and conventionalslurries, it is noted that conventional slurries have viscositiesbetween about 10-200 mPa-s and contain an amount of water between about50-70% by weight.

Another reason that non-heated air may be used in the spray dryingsystem 100 (and process) relates to an unconventional electrostaticcharging process that is conducted before, during or after atomization.In particular, an electrostatic charge is applied to the slurry or tothe atomized droplets 108, preferably the former. In this regard, thesystem 100 includes a high voltage supply 104 (such as about 45 kV DC)that is coupled to one or more electrodes (not shown in FIG. 2). Thepolarity of the high voltage supply 104 may be in either the positive ornegative configuration. The slurry (or atomized droplets 108) is broughtinto contact with the electrode to impart an electrical charge thereto.In a preferred embodiment, the slurry is brought into contact with theelectrode(s) in order to produce a charged slurry. Concurrently orthereafter, the charged slurry is atomized to produce a plurality ofelectrostatically charged, wet particles (droplets) 108.

The respective charge on the wet droplets 108 produces a force thattends to cause adjacent droplets to repel one another. Additionally, theforce on a given droplet 108 opposes the surface tension of such givendroplet 108. When the charge on the given droplet 108 exceeds athreshold level, the Rayleigh limit, the droplet 108 becomes unstableand smaller satellite droplets 108 are ejected from the given (parent)droplet 108. One or more of the satellite droplets 108, in turn, mightalso become unstable and produce additional satellite droplets 108,since the surface charge density does not diminish in the satellitedroplets 108 as evaporation takes place.

The electrostatically charged, wet particles/droplets 108 are suspendedfor a sufficient time within the drying chamber 107 to permit theaforementioned repulsive forces induced by the electrostatic charge onat least some wet particles/droplets 108 to cause at least some of suchparticles to divide into wet sub-particles/droplets 108. The suspensionof the droplets 108 continues, without the presence of any heated dryingfluids, for a sufficient time to drive off a sufficient amount of theliquid solvent within most of the wet particles/droplets 108 to leave aplurality of dried particles (the powder), each dried particlecontaining the active ingredient encapsulated within the carrier.Notably, the production of sub-particles/droplets 108 from a givenvolume of atomized slurry (i.e., from a given droplet 108) results infaster drying of such volume due to a greatly increased aggregatesurface area of the sub-particles/droplets 108 and concomitant reductionof particle volume of each sub-particle/droplet 108 following eachfission event.

The production of sub-particles/droplets 108 may be referred to ascoulombic fission. The time scale for such coulombic fission events ison the order of a few microseconds to milliseconds. The fission of aboutten (10) sub-particles/droplets 108 from a given particle/droplet 108reduces a diameter of the given particle/droplet 108 by about 30%. Theamount of time that it takes to achieve such reduction in diameter (onthe order of a few microseconds to milliseconds) is an order ofmagnitude faster than diffusive evaporation in the presence of heatedair, which occurs with a characteristic time t in accordance with thefollowing formula:

t=do ² /k

where do is the diameter of the particle and k is the evaporativediffusion coefficient. For particles in the 20 to 200 mm diameter range,the time to any significant diameter reduction by evaporation is on theorder of tenths to several seconds, which is far longer (one to twoorders of magnitude) than diameter reduction by coulombic fission.

The individual or combined characteristics of relative low water contentin the slurry and electrostatic charge on the droplets 108 permitsvastly a different temperature condition within the drying chamber 107as compared with prior art systems and processes. For example, atemperature of the non-heated drying fluid (air) introduced into thedrying chamber 107 may be at least one of: less than about 100° C.; lessthan about 75° C.; less than about 45° C.; less than about 35° C.; lessthan about 30° C.; and at about an ambient temperature of a room withinwhich the drying chamber 107 is located. The above temperature rangesassume a lower limit above freezing.

It has been demonstrated that an inlet air temperature of about 40° C.may result in an outlet air temperature of about 32° C. from the dryingchamber 107.

While elevated temperatures as compared to the convention spray dryingprocess of the prior art may not be necessary, it may be desirable toensure that the drying fluid (air) introduced into the drying chamber107 is of relatively low water content. Thus, the system 100 may includethe process dehumidifier 110 in order to remove some amount of waterfrom the air prior to introduction into the drying chamber 107. Afterdehumidification, the non-heated air as input into the drying chamber107 may be at a relative humidity of about 7%.

The atomizer 106 may be implemented by way of any of the known methods,apparatus, and/or techniques. For example, the atomizer 106 may beimplemented using at least one of: a nozzle technique, a centrifugaltechnique, a pneumatic technique, and an ultrasonic technique. For mostatomization techniques, the slurry does not leave the atomizingmechanism as a final droplet 108, but rather as a fragment of a thinliquid film or ligament. The formation of droplets 108 takes placeimmediately after the liquid has left the atomizing mechanism, due tothe surface tension of the liquid. The droplet size from a given type ofatomization depends on the energy input into breaking the slurry intofragments, i.e., increasing the overall effective surface area of theslurry.

The average droplet size and distribution may be fairly constant for agiven atomization technique, and may be in the range of 10-300 microns.The electrostatic charge process and resultant coulombic fission processin accordance with the various embodiments herein produces, in general,larger particles than conventional spray drying processes. The largerparticles, however, come from even larger, parent particles, whichconventional atomizers cannot adequately produce. The daughter particlesproduced in accordance with the embodiments herein are smaller, and theprocess tends to make bimodal size distributions for very viscousslurries.

Centrifugal (or rotary) atomization may be considered the most commonform of atomization. Centrifugal atomization employs a rotating disc orwheel, which breaks the liquid stream of slurry into droplets. Thecentrifugal atomization device may employ a disc or wheel of about 5 to50 cm in diameter, which spins in the range of about 5,000 to 40,000rpm. The size of the droplets 108 produced by a centrifugal atomizationdevice is about inversely proportional to the peripheral speed of thedisc or wheel.

Nozzle atomization employs a pump (e.g., the feed pump 5 of FIG. 2),which pressurizes and forces the slurry through the orifice of a nozzleto break the liquid into fine droplets. The orifice size is usually inthe range of 0.5 to 30 mm. The size of the droplets depends on the sizeof the orifice and the pressure drop. A larger pressure drop across theorifice produces smaller droplets. Therefore, to reduce theparticle/droplet size for a given feed rate, a smaller orifice and ahigher pump pressure may be employed.

Two-fluid pneumatic atomization employs the interaction of the slurrywith another fluid, usually compressed air using a fluid nozzle for thecompressed air and a fluid nozzle for the slurry. The pressure of theair and slurry may be in the range of about 200 to 350 kPa. Particlesize is controlled by varying a ratio of the compressed air flow to thatof the slurry flow.

Sonic atomization employs ultrasonic energy to vibrate a surface atultrasonic frequencies. The slurry is brought into contact with thevibrating surface in order to produce the particles/droplets 108.

With reference to FIGS. 3-5, one or more embodiments of the presentinvention may employ a nozzle-type atomizer 106. FIG. 3 is across-sectional view of a two-fluid atomizer 200 that may be employed asthe atomizer 106 in the system of FIG. 2 in order to produce the wetparticles/droplets 108 from the slurry. FIG. 4 is a cross-sectional viewof a distal end of the two-fluid atomizer 200 of FIG. 3, and FIG. 5 is aperspective, exploded view of certain components of the distal end ofthe two-fluid atomizer 200 of FIG. 4.

The two-fluid atomizer 200 includes a body 202 having a proximal end 204and a distal end 206. A channel 208 extends through the body 202 andincludes an inlet 210, generally near the proximal end 204 of the body202, and an outlet 212, generally near the distal end 206 of the body202. The channel 208 operates to convey a first of the two-fluids, i.e.,the slurry, from the inlet 210 to the outlet 212.

The two-fluid atomizer 200 also includes at least one electrode 214operating to contact the slurry and apply an electrostatic chargethereto, such that the two-fluid atomizer 200 operates to produce aplurality of electrostatically charged wet particles/droplets 108. Inone or more embodiments, the at least one electrode 214 may be disposedwithin the body 202 of the two-fluid atomizer 200 such that the slurrycontacts the electrode 214 and becomes electrostatically charged whileflowing from the inlet 210 to the outlet 212 of the channel 208. Asillustrated in FIG. 3, the electrode 214 may be disposed within thechannel 208, preferably in a coaxial arrangement, such that asignificant portion of the surface area of the electrode 214 isavailable for contact with the slurry. The electrode 214 may be insertedinto the channel 208 by way of a threaded bore of the body 202 andcomplementary threaded shaft of the electrode 214, which when engaged,positions the electrode within the channel 208. A connection terminal216 may be electrically and mechanically coupled to the electrode 214 inorder to provide a means for connecting with the high voltage supply 104and receiving voltage potential at the surface of the electrode 214.

With reference to FIGS. 3 and 4, the two-fluid atomizer 200 may includea nozzle 220 in fluid communication with the outlet 212 of the channel208. In particular, the outlet 212 of the channel 208 includes a tube224 sized and shaped to engage, and be received within, a complementarybore 226 at an inlet end 228 of the nozzle 220. The engagement of thetube 224 and bore 226 permits fluid communication of the slurry (whichhas been electrostatically charged) from the channel 208 into aninternal volume 230 intermediately disposed within the nozzle 220. Asealing ring 232 may be employed to ensure a fluid tight seal betweenthe tube 224 and the bore 226, even under fluid pressure. The nozzle 220preferably includes a transition section 234 of reducing diameter (atapering surface) extending from the internal volume 230 to a nozzleorifice 236. The nozzle orifice 236 is preferably of a generallycylindrical shape, including an internal bore of a size sufficient toproduce wet particles/droplets 108 of desired size and shape once theysuccumb to surface tension forces.

The two-fluid atomizer 200 may further include a nozzle cap 222, whichgenerally surrounds the nozzle 220 and permits the nozzle orifice 236 toextend through a bore 266 at a distal end thereof. The nozzle cap 222includes an engagement feature at a proximal end thereof, which engagesthe distal end of the body 202. In particular, the nozzle cap 222includes a threaded shank 238, which threads into a complementarythreaded bore 240 of the body 202. A sealing ring 242 may be employed toensure a fluid tight seal as between an internal surface 244 of thenozzle cap 222 and an external surface 246 of the nozzle 220, therebyforming an internal volume 248 therebetween.

The two-fluid atomizer 200 includes another channel 250 extendingthrough the body 202, which includes an inlet 252, generally near theproximal end 204 of the body 202, and an outlet 254, generally near thedistal end 206 of the body 202. The channel 250 operates to convey asecond of the two-fluids, i.e., the non-heated air, from the inlet 252to the outlet 254. The outlet 254 is in fluid communication with theinternal volume 248 (between the internal surface 244 of the nozzle cap222 and the external surface 246 of the nozzle 220). Thus, the channel250 operates to convey the non-heated air from the proximal end 204 tothe distal end 206 of the two-fluid atomizer 200. The flow of thenon-heated air through the two-fluid atomizer 200 may be about 5100m³/hr at an input pressure of about 130 psi.

As best seen in FIGS. 4-5, the nozzle 220 includes a tapered surface 260on an exterior thereof, which is downstream of the exterior surface 246and downstream of the internal volume 248. The nozzle cap 222 includes acomplementary internal surface in abutment with the tapered surface 260.A number of grooves (recesses) 262 are disposed in the tapered surface260 and extend from the internal volume 248 toward the nozzle orifice236. When the complementary internal surface of the nozzle cap 222 is inabutment with the tapered surface 260, the grooves 262 provide fluidcommunication of the non-heated air from the internal volume 248 towardthe nozzle orifice 236. The grooves terminate at an annular space 264between a peripheral edge of the tapered surface 260 and the outersurface of the nozzle orifice 236, where the nozzle orifice 236 exitsthe nozzle 220. The annular space 264 is in fluid communication with thebore 266, whereby a suitably sized bore (larger than a diameter of thenozzle orifice 236) permits the non-heated air to exit the nozzle 220and nozzle cap 222 under pressure. Preferably, the grooves 262 extendsuch that they terminate tangentially to the annular space 264 andthereby cause the non-heated air to produce a swirling fluid motionwithin the space 264 and in the vicinity of the nozzle orifice 236 afterit has exited the bore 266.

The swirling fluid motion of the non-heated air, as it leaves the nozzle220 and nozzle cap 222, imparts a swirling agitation to the plurality ofwet particles/droplets 108 as they leave the nozzle 220. Such swirlingagitation may suspend and agitate the wet particles/droplets 108 inorder to achieve the aforementioned fission and evaporation. The aboveapproach to atomization enables relatively high slurry throughput, onthe order of 1-20 kg/hr at an input pressure of about 20-100 psi.

Reference is now made to FIG. 6, which is a schematic, side view of adrying chamber 107 that may be employed in the system 100 of FIG. 2 inaccordance with one or more aspects of the present invention. The dryingchamber 107 may include an inlet end 300, an outlet end 302, and aninternal volume 304, within which the wet particles/droplets 108 aredried. The drying chamber is formed from a non-electrically conductivematerial. It is noted that the choice of materials (in this case anon-electrically conductive material, a non-metal) is not a mere matterof obvious design choice. Indeed, the conventional wisdom of the priorart spray drying process requires heated air (on the order of 200° C.),which consequently requires a metal drying chamber (typically stainlesssteel), otherwise the chamber would warp or otherwise fail.

A benefit of using non-heated air (which is directly counter to theconventional wisdom in the spray drying art) is that the drying chamber107 may be formed from a non-metallic material; indeed, the temperatureinside the drying chamber 107 may be less than 50° C. Thus, materialssuch as polymer-based composites may be employed for implementing thebasic drying chamber 107. By way of example, filament wound fiberglasscomposite tanks (which are used for storage of water, various foodstuffs, grain storage, brines and many non-food based applications) haveexcellent load carrying properties and can be used for making very largetanks. In one or more embodiments, such filament wound fiberglasscomposite materials may be used to fabricate the drying chamber 107discussed herein. An advantage of using engineered plastics is the lowercost of the basic materials and the cost of manufacturing when comparedto similar sized vessels made from stainless steel, for example. Thesematerials also enable greater flexibility in the design of the dryingchamber 107, making complex shapes possible, which are much moredifficult and expensive to manufacture from stainless steel.

The use of non-metallic, non-conducting dielectric materials to form thedrying chamber 107 (such as the engineered plastic composite materials),permits the use of one or more electric fields within the drying chamber107 itself, to urge the particles/droplets 108 into desired trajectoriesand/or to urge such particles/droplets 108 from the inlet end 300 towardthe outlet end 302 of the drying chamber 107. Notably, it is virtuallyimpossible to develop an electric field inside a metallic, conductivevessel of the prior art because all charge accumulates on the surface ofthe vessel.

In accordance with one or more embodiments, the drying chamber 107 mayinclude a first electrode 310 located at or near the inlet end 300thereof, and a second electrode 312 located at or near the outlet end302 of the drying chamber 107. The application of a source of voltagepotential between the first and second electrodes 310, 312 induces anelectric field (illustrated as broken lines) within the drying chamber107 sufficient to urge the particles/droplets 108 into desiredtrajectories as they dry within the chamber 107. One such desirabletrajectory is to cause the lines of the electric field to extendgenerally parallel to the walls of the drying chamber 107, even wheresuch walls taper toward the outlet end 302. To achieve such trajectory,the second electrode 312 would have to be of a relatively small diameteras compared to the first electrode 310 (as is depicted by only the solidportion of the line of the electrode 312.) If the first and secondelectrodes 310, 312 are of generally the same diameter, then the linesof the electric field would extend generally parallel to the walls ofthe drying chamber 107, and then pass through the tapered walls at theoutlet end 302. Other particle trajectories may be achieved based onnumber, location, size, and shape of the electrodes. As illustrated, thefirst and second electrodes 310, 312 may be disposed external to thedrying chamber 107, yet induce an electric field within the internalvolume 304 of the drying chamber 107 by virtue of the formation thereoffrom non-electrically conductive material.

To illustrate the utility of the no heat spray drying process forprobiotic applications, Dannon™ Aunatural plain yogurt was subject tospray drying process described herein. In order to show that thebacteria (called L.acidophilus) survived the process, the spray driedyogurt was used to produce a new culture of yogurt. Since yogurt isapproximately 85% water by weight, a slurry was formed using 643 gramsof starch M180 and 357 grams of yogurt to make 1 kg batch of slurry. Thestarch to yogurt ratio was about 1.8. The slurry was subject to theno-heat drying process discussed above with respect to FIG. 2 andrelated illustrations. The resulting powder was then mixed with milk anda new yogurt culture was produced. A control culture using some of theoriginal yogurt was also made. The spray dried bacteria produced thesame amount of culture as the control using comparable starting weightsof bacteria.

Reference is now made to FIGS. 7-8, which respectively are an image ofdried powder non-fibrous particles produced using the system of FIG. 2,and a cross-section through one of the dried powder particles of FIG. 7.As can be seen in the scanning electron images, the dried particlemorphology benefits from a no-heat process in that the particles do notexperience an abrupt rise in temperature as they enter the dryingchamber and the particles do not exhibit cracks on the surface, volcanostructures on the surface, or hollow regions within the particles. Thecross-section of the particle shows a uniform distribution ofencapsulated constituent component(s), in this case flavor oil droplets,in the micron-diameter range.

Reference is now made to FIGS. 9-10, which respectively are scanningelectron images of dried powder fibers produced using the system of FIG.2, and a cross-section through one of the dried powder fibers. Throughmodifications of the emulsion of the slurry, it is also possible toproduce fibers instead of particles. For example, to make fibers one maychange the carrier material (e.g., the starch) to a lower DE (dextroseequivalent), such that the concentration level at which an “entanglementtransition” occurs is crossed. At such concentration level, the largestarch molecules interact in a manner such that the slurry begins tomanifest extensional viscoelastic properties that permit fibers to form.As can be seen in the scanning electron images, the dried fibermorphology is also characterized by a lack of cracks on the surface,volcano structures on the surface, or hollow regions within the fibers.The cross-section of the fiber also shows a uniform distribution ofencapsulated constituent component(s), in this case flavor oil droplets,in the micron-diameter range.

Reference is now made to FIG. 11, which is a graph illustrating theweight percentage of the desired component(s) within dried powderparticles produced using the system of FIG. 2 as compared with theconventional spray drying process. The no-heat process has demonstratedhigher levels of preservation of starting active ingredients such asvolatile flavor molecules. FIG. 11 shows the results of a 1000 houraccelerated aging study (at elevated temperatures of about 95° F.)comparing powders produced by conventional spray dry processing and theno-heat process. In the illustrated results, amounts of a particularconstituent component, in this case a principle molecular type calledD-Limonene (obtained from orange oil), were measured in an un-processedsource of flavor oil 400, dried powder 402 produced in accordance withthe no-heat process described herein, and dried powder 404 produced inaccordance with the prior art heated air process. As FIG. 11 clearlyshows, the no-heat powder 402 retains essentially the same flavor oilcomposition as the original oil source 400 used to produce the startingslurry, whereas the conventionally spray dried powder 404 departssignificantly from the original starting oil 400. Similar results werefound for all other principal constituents of other flavor oils.Additionally, the appearance of degradation products was greatlydiminished in the no-heat samples, resulting in longer projectedshelf-life of the powder.

The above data reveal that not only are some of the structures andprocesses of the system 100 of FIG. 2 inventive, but the dried powder(or fiber) itself is inventive. Indeed, the resultant dried powder (orfiber) includes a plurality of dried particles/fibers, whichindividually contain an amount of final active ingredient encapsulatedwithin a carrier resulting from drying the slurry, which contained aninitial active ingredient, a liquid solvent and the carrier. The initialactive ingredient includes one or more constituent components, at leastone of which is among one or more principle molecular types from whichat least one of a desirable food, flavor, fragrance, medicament,bacteria, probiotic, pigment, etc. is obtained. The final activeingredient includes one or more of the constituent componentscorresponding with those of the initial active ingredient as modified bythe drying of the slurry. A weight percentage of at least one of the oneor more principle molecular types in the final active ingredient isessentially the same (e.g., within about 5%, 4%, 3%, or 1% of a) weightpercentage of the corresponding principle molecular types in the initialactive ingredient.

Another way to characterize the inventive characteristics of the driedpowder/fibers is that a weight percentage of at least one of the one ormore principle molecular types in the active ingredient does not varysignificantly (not by more than about 5%, 4%, 3%, 2%, or 1%) duringaging of the dried powder during any period of elevated temperature ofabout 95° F. up to about 1000 hours.

The present disclosure provides a new method of spray drying, using alow temperature, e.g., “no heat”, spray drying process that producespowder products with superior flavor retention and stability. The spraydrying method of the present disclosure does not employ purposely heatedgas for removing water from the atomized fluid droplets, as has been thecase in previously employed spray drying operations. The spray dryingmethod of the present disclosure instead uses unheated air, e.g.,dehumidified air, to carry out high throughput atomization processes,utilizing unique dryer designs and high solids content (low watercontent) slurries/emulsions with extremely high viscosities (forexample, viscosities in a range of from 500 to 10000 mPa-s) to producepowders dried at low temperatures, such as temperatures on the order offrom 5 to 50° C.

In specific embodiments, the air utilized in the spray drying operationmay have a relative humidity of 10% or less, e.g., less than 8%, 7%, 6%,5%, 4%, 3%, 2%, or 1%. The dewpoint of such air may be in a range offrom −20° C. to 5° C., such as in a range of from −15° C. to 5° C., from−12° C. to 3° C., from −12° C. to 0° C., from −12° C. to −5° C., or anyother suitable dewpoint range appropriate to the spray drying operation.

The use of high solids content emulsions (with solids concentrations ofat least 40% by weight, based on total weight of the emulsion, andpreferably at least 50% by weight on the same total weight basis) in thelow temperature, e.g., no heat, spray drying process of the presentdisclosure provides a host of desirable attributes to the final powdersproduced by the process, such as: (1) high particle density, withdensity greater than that of water (i.e., >1 g/cc), so that theparticles readily sink into aqueous solution and become rapidlydissolved or suspended, (2) greater resistance to oxidation imparted bythe higher solids content, (3) substantial energy efficiency from theuse of high solids content slurries/emulsions coupled with lowtemperatures, since about half as much water is evaporated as comparedto traditional spray drying processes, and (4) superior retention ofhigh value active ingredients such as flavors or fragrances, as anothersubstantial economic advantage brought about by low temperature dryingand high solids content slurries/emulsions.

By contrast, conventional high temperature drying processes lose asignificant amount of the highly volatile flavor or fragrance activeconstituents to evaporation and oxidation, resulting in powders withless desirable flavor and aroma attributes. These powders resulting fromhigh temperature conventional processes are typically of small averagediameter, e.g., on the order of 60-100 micrometers, are not fully dense,and are difficult to dissolve in aqueous solutions. Powders produced bythe low temperature spray drying process of the present disclosure, bycontrast, have large average diameters, such as on the order of 125-250micrometers, are fully dense, and readily go into solution.

The spray drying process of the present disclosure as a consequence ofits low temperature, e.g., no heat, character, may be utilized forpreparation of spray dried products that contain highly volatilecomponents, e.g., volatile active ingredients whose boiling points areless than 100° C., and may for example be less than 90° C., 80° C., 70°C., 65° C., 60° C., 55° C., 50° C., 45° C., 40° C., 35° C., or evenlower.

The spray drying process of the present disclosure may be employed toform spray dried powders and fibers in which one or more of theprinciple molecular types include aldehydes such as acetaldehydes,valeraldehyde, iso-valeraldehyde, etc., dimethyl and other alkylsulfides, acetates such as ethyl acetates and other alkyl acetates,proprionates such as ethyl proprionate, alkyl butyrates such as methylbutyrate and ethyl butyrate, ketones, esters, etc.

Spray dried powders and fibers of the present disclosure, whereinvolatile active ingredient(s) are highly retained, may be incorporatedinto any suitable products, such as for example beverages, sportsbeverages, nutritional beverages, gums, dairy products, soups, sauces,condiments, baked goods, personal-care products, oral care products,detergents, fresheners, etc.

Spray dried powders and fibers of the present disclosure thus can beproduced in which the final active ingredient includes one or more ofthe constituent components corresponding to those of the initial activeingredient as modified by the spray drying process, wherein the spraydried powder or fiber composition has at least one of thecharacteristics of (i) a weight percentage of at least one of the one ormore principle molecular types in the final active ingredient which iswithin about 15% of a weight percentage of the corresponding principlemolecular types in the initial active ingredient, and which may forexample be within about 12%, 10%, 8%, 7%, 6%, 5%, 4%, 3%, 2% or 1% ofthe weight percentage of the corresponding principle molecular types inthe initial active ingredient, and (ii) a weight percentage of at leastone of the one or more principle molecular types in the final activeingredient which does not vary by more than about 15% during aging ofthe dried powder or fiber during any period of elevated temperature ofabout 95° F. up to about 1000 hours, and which may for example not varyby more than about 12%, 10%, 8%, 7%, 6%, 5%, 4%, 3%, 2% or 1% duringsuch aging.

The present disclosure thus embodies a novel approach for slurry oremulsion formulation for use in a low/no heat spray drying process,resulting in greatly improved powder properties and sensorycharacteristics of taste, aroma, etc.

In addition to having broad utility for processing of a wide variety ofnatural and artificial products, the spray drying process of the presentdisclosure is useful in the context of increasing utilization of naturalproducts, including the proliferating use of essential oils extractedfrom natural sources. Essential oils are composed of wide ranges oflipophilic and highly volatile components covering a diverse spectrum ofchemical classes. Essential oils, however, are susceptible to conversionand degradation reactions. Heat and light exposure and oxygenavailability can significantly impact essential oil integrity. The lowtemperature spray drying process of the present disclosure substantiallymitigates the degrading effects of heat and oxidation on theencapsulated flavor oil, as is illustrated in the following examples.

EXAMPLE 1

D-limonene Assessment

In order to demonstrate some of the important advantages of the “noheat” spray dry process over traditional spray dry processing, flavorpowders prepared by both methods were subjected to an accelerated agingtest. The test powders were placed into an oven maintained at atemperature of 95° Fahrenheit. Once every seven days a sample of eachpowder was analyzed via gas chromatography mass spectrometry (GC-MS)analysis to determine the presence or absence of key molecularconstituents. The flavor oil for analysis was extracted from the powdersamples using standard procedures.

The results for both conventionally spray dried and no heat spray driedpowders were also compared to a control sample of the starting neatflavor oil (“Neat Oil”) subjected to the same storage conditions as thepowders. The test was run for a period of 9 weeks. This test simulatesdegradation processes that a powder will experience over its shelf life.The primary degradation processes are oxidation of key flavor molecules,with the oxidation products being the cause of spoilage and developmentof “off” taste in the product. The GC-MS comparison also revealsdeficits in key flavor constituents due to evaporation that occurredduring the spray dry processing as compared to the starting flavor oilcontrol sample.

In this study a lemon-lime flavor oil was selected because it is highlyrepresentative of the key volatile essential oil flavor molecules (topnotes) that are present in a wide range of citrus based flavors. Thesekey flavor molecules are highly susceptible to oxidation, have lowboiling points, and are easily evaporated.

The emulsions for both samples contained a 10% by weight load of thelemon-lime flavor oil. Both emulsions used a carrier starch andemulsifier. The spray drying emulsion in accordance with the presentdisclosure (Sample A, “Zoom”) contained 30% water, 6% starch emulsifier,and the remainder was 54% starch (all percentages by weight, based ontotal weight of the composition) and was spray dried at an inlet airtemperature of 42° C. The sample for traditional spray dry processing(Sample B, “Spray”) was produced by Adron, Inc., (94 Fanny Rd, Boonton,N.J. 07005, USA), using the same lot of lemon lime flavor oil.

The most abundant and readily perceived molecule in citrus flavors isd-limonene. D-limonene is a volatile top note component, which adds tothe fresh, light, lemon, orange, and sweet citrus notes in the flavor. Adecrease of d-limonene concentration in the citrus flavor compositiondramatically alters the citrus flavor in an undesirable manner. Whencitrus oils spoil it is primarily due to oxidation of d-limonene.Oxidation decreases the d-limonene concentration, thereby giving rise tovarious unwanted oxidation products, such as p-cymene, p-cymene-8o1,epoxides, menthadienols, and gamma-terpinene.

FIG. 12 compares the mass spectrometric results for d-limonene contentin the control neat lemon-lime oil (“Neat Oil”), the traditional spraydried powder (Sample B, “Spray”) and the low temperature spray driedpowder in accordance with present disclosure (Sample A, “Zoom”). In FIG.12, d-limonene content is plotted as a function of time of exposure tohot air at a temperature of 95° F., over a period of 9 weeks. Thetraditional spray dry powder (“Spray”) exhibited severe degradation ofd-limonene, as compared to the control neat oil (“Neat Oil”) and the lowtemperature dried powder of the present disclosure (“Zoom”).

These results illustrate two important findings. First, theconcentration of d-limonene in the traditional spray dried powder waslower than the control and the Zoom dried samples from the outset,reflecting the occurrence of evaporation that takes place during thetraditional spray drying process due to the presence of heat as thepowder is made. Second, as time progressed, the concentration ofd-limonene continued to decrease in the traditionally spray driedsample, while the control neat oil and Zoom dried samples did not showany significant degradation.

EXAMPLE 2

Gamma-Terpinene Assessment

Gamma-terpinene is normally present in lemon and lime oils, andcontributes to the top note of the flavor. When gamma-terpinene oxidizesthe principal oxidation product is para-cymene (p-cymene). Theconcentration of gamma-terpinene as a function of time is shown in FIG.13, for the control neat oil (“Neat Oil”), the traditional spray driedpowder (Sample B, “Spray”) and the low temperature spray dried powder inaccordance with present disclosure (Sample A, “Zoom”). FIG. 13 shows acomparison of the gamma-terpinene content as a function of time ofexposure to hot air at a temperature of 95° F. There was a relativelyfast decrease in gamma-terpinene concentration in the traditional spraydried powder within the first two weeks of testing. The control neat oiland Zoom dried powder showed a slight decrease over the 9 week period.

FIG. 14 is a comparison of para-cymene oxidation product forcorresponding samples of the he control neat oil (“Neat Oil”), thetraditional spray dried powder (Sample B, “Spray”) and the lowtemperature spray dried powder in accordance with present disclosure(Sample A, “Zoom”). The increased presence of p-cymene as seen in FIG.14 is an indication of ongoing oxidation reactions. The presence ofp-cymene produces an off-bitter tasting profile. As FIGS. 13 and 14indicate, in the traditional spray dry powder, the gamma-terpineneconcentration decreased just as quickly as the p-cymene concentrationwas increasing, reflecting a faster rate of oxidation in comparison tothe Zoom dried powder and the control neat oil.

EXAMPLE 3

Alpha/Gamma Terpineol Assessment

Terpineols are a small constituent of citrus oils, which contribute toheavier, less fresh tastes. It is well known that alpha and gammaterpineols can be produced from limonene. The increased presence ofalpha and gamma terpineol indicate ongoing oxidation processes.

FIG. 15 shows the concentration of alpha and gamma terpineols as afunction of time, for the control neat oil (“Neat Oil”), the traditionalspray dried powder (Sample B, “Spray”) and the low temperature spraydried powder in accordance with present disclosure (Sample A, “Zoom”).FIG. 15 shows a comparison of the alpha and gamma terpineols content asa function of time of exposure to hot air at a temperature of 95° F.There was a large initial rise in the concentration of terpineols in thepowder made by the traditional spray dry process. The concentration ofterpineols in the Zoom dried powder and in the control neat oil sampleremained constant over the course of the test indicating very low ornonexistent terpineol production.

EXAMPLE 4

Limonene/Terpinolene Epoxide Formation and P-Menthadienol Formation

The formation of limonene and terpinolene epoxides and p-menthadienolare the result of oxidation processes. These unwanted byproducts formfar more rapidly in traditional spray dry powders than in the controlneat oil or the Zoom dried powder, as shown by the results in FIG. 16.

FIG. 16 shows the concentration of limonene and terpinolene epoxide as afunction of time, for the control neat oil (“Neat Oil”), the traditionalspray dried powder (Sample B, “Spray”) and the low temperature spraydried powder in accordance with present disclosure (Sample A, “Zoom”).FIG. 16 shows a comparison of the limonene and terpinolene epoxidecontent as a function of time of exposure to hot air at a temperature of95° F. The epoxide concentration increased rapidly over the first 5weeks, indicating a more rapid rate of oxidation in the traditionallyspray dried powder.

Similar results are shown in FIG. 17 in the concentration ofp-menthadienol , for the control neat oil (“Neat Oil”), the traditionalspray dried powder (Sample B, “Spray”) and the low temperature spraydried powder in accordance with present disclosure (Sample A, “Zoom”),as a function of time of exposure to hot air at a temperature of 95° F.The data show a continuing rise in the concentration of p-menthadienolin the traditionally spray dried sample.

EXAMPLE 5

Trans-and Cis-Carveol Assessment

Trans-and cis-carveol are also formed as a result of oxidation oflimonene. Their concentration in the neat oil is very low. When theconcentration of these constituents becomes too high in a citrus oil, itindicates the occurrence of spoilage, and results in an off-taste.

FIG. 18 shows the concentration of trans-and cis-carveol, for thecontrol neat oil (“Neat Oil”), the traditional spray dried powder(Sample B, “Spray”) and the low temperature spray dried powder inaccordance with present disclosure (Sample A, “Zoom”), as a function oftime of exposure to hot air at a temperature of 95° F. The data showthat trans-and cis-carveol form at a much more rapid rate in thetraditional spray dried powder than in either the control neat oil or inthe Zoom dried powder.

EXAMPLE 6

P-Cymeme-8-ol Assessment

This assessment involved the determination of the oxidation productp-cymene-8-ol in the control neat oil (“Neat Oil”), the traditionalspray dried powder (Sample B, “Spray”) and the low temperature spraydried powder in accordance with present disclosure (Sample A, “Zoom”),as a function of time of exposure to hot air at a temperature of 95° F.

The results are shown in FIG. 19, as a graph of the concentration ofp-cymene-8-ol, in weight percent, based on the weight of the sample, asa function of time for the 9 week assessment period. As shown by thedata, the concentration of p-cymene-8-ol like p-cymene in the controlneat oil was very low. Increases in concentration of p-cymene-8-ol areindicative of ongoing oxidation reaction. The increased formation ofp-cymene-8-ol in the traditional spray dried powder when compared to theZoom dried powder or the control neat oil, show that the spray driedsample was being oxidized faster than the Zoom dried sample, or the neatoil.

The foregoing empirical results show the substantially increasedstability of spray dried products that is achievable by the “no heat”spray drying process of the present disclosure. These results show thatsuch no heat spray drying process achieves extremely low loss ofvolatile flavor components that would otherwise occur as a result ofevaporation and that the incidence of oxidative reactions in the spraydried powders of the present disclosure are greatly reduced, as comparedwith the levels that occur in traditional spray dried products. Thespray dried powder products of the present disclosure retaindramatically higher levels of highly volatile and critical top notecomponents of flavor oils. As a result, the shelf lives of spray driedpowder products of the present disclosure greatly exceed those oftraditional spray dried powder products.

What is claimed is:
 1. A method of spray drying an ingredient into adried powder, comprising: forming a slurry including water, a carrier,and the ingredient, wherein the slurry has a viscosity in a range offrom 500 to 16,000 mPa-s, and contains from 20 to 50 wt % water;atomizing the slurry to generate a spray of liquid droplets of theslurry; introducing the spray of liquid droplets of the slurry into adrying chamber; and feeding air at temperature less than 100° C. intothe drying chamber to dry the liquid droplets to form the dried powdercomprising a plurality of dried particles containing the ingredientencapsulated within the carrier.
 2. The method of claim 1, whereinweight loss of the ingredient in the method does not exceed 5 wt %. 3.The method of claim 1, wherein weight loss of the ingredient in themethod does not exceed 3 wt %.
 4. The method of claim 1, wherein weightloss of the ingredient in the method does not exceed 2 wt %.
 5. Themethod of claim 1, wherein weight loss of the ingredient in the methoddoes not exceed 1 wt %.
 6. The method of claim 1, wherein the slurry hasa viscosity in a range of from 1000 to 4000 mPa-s.
 7. The method ofclaim 1, wherein the slurry contains from 20 to 45 wt % water.
 8. Themethod of claim 1, wherein the slurry contains from 20 to 40 wt % water.9. The method of claim 1, wherein the air is not heated in the method.10. The method of claim 1, wherein the air is fed into the dryingchamber at temperature less than 75° C.
 11. The method of claim 1,wherein the air is fed into the drying chamber at temperature less than45° C.
 12. The method of claim 1, wherein the air is fed into the dryingchamber at temperature less than 35° C.
 13. The method of claim 1,wherein the air is fed into the drying chamber at temperature less than30° C.
 14. The method of claim 1, wherein the air is fed into the dryingchamber at an ambient temperature of the drying chamber.
 15. The methodof claim 1, further comprising dehumidifying the air before it is fedinto the drying chamber.
 16. The method of claim 1, wherein the spray ofliquid droplets has an average droplet size in a range of from 10 to 300μm.
 17. The method of claim 1, wherein the atomizing comprises nozzleatomization, centrifugal atomization, pneumatic atomization, orultrasonic atomization.
 18. The method of claim 1, wherein the atomizingcomprises imparting a swirling fluid motion to the spray of liquiddroplets of the slurry introduced into the drying chamber.
 19. Themethod of claim 1, wherein the atomizing is conducted at an inputpressure in a range of from 20 to 100 psi.
 20. The method of claim 1,wherein the ingredient is a food ingredient.
 21. The method of claim 1,wherein the ingredient is a flavor ingredient.
 22. The method of claim1, wherein the ingredient is a fragrance ingredient.
 23. The method ofclaim 1, wherein the ingredient is a medicament ingredient.
 24. Themethod of claim 1, wherein the ingredient is a probiotic ingredient. 25.The method of claim 1, wherein the ingredient is a pigment ingredient.26. The method of claim 1, wherein the ingredient is a flavor oilingredient.
 27. The method of claim 1, wherein the dried powdercomprises dried powder fibers.
 29. The method of claim 1, wherein thedried powder comprises dried particles and dried powder fibers.
 30. Themethod of claim 1, wherein the method is conducted so that the driedpowder when subjected to aging at elevated temperature of 95° F. for1000 hours does not lose more than 5% of the weight of the ingredienttherein.
 31. The method of claim 1, wherein the method is conducted sothat the dried powder when subjected to aging at elevated temperature of95° F. for 1000 hours does not lose more than 4% of the weight of theingredient therein.
 32. The method of claim 1, wherein the method isconducted so that the dried powder when subjected to aging at elevatedtemperature of 95° F. for 1000 hours does not lose more than 3% of theweight of the ingredient therein.
 33. The method of claim 1, wherein themethod is conducted so that the dried powder when subjected to aging atelevated temperature of 95° F. for 1000 hours does not lose more than 2%of the weight of the ingredient therein.
 34. The method of claim 1,wherein the method is conducted so that the dried powder when subjectedto aging at elevated temperature of 95° F. for 1000 hours does not losemore than 1% of the weight of the ingredient therein.